Automatically applying components based on crash stacktrace and information from OWNERS files.

If this is incorrect, please apply the Test-Predator-Wrong-Components label.

Automatically assigning owner based on suspected regression changelist https://chromium.googlesource.com/chromium/src/+/534a77d736cc20e640ba713c5e5eca40bace6366 (More cases of explicit output clip of effect nodes).

If this is incorrect, please let us know why and apply the Test-Predator-Wrong-CLs label. If you aren't the correct owner for this issue, please unassign yourself as soon as possible so it can be re-triaged.

Issue 889988 has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/df9f7af7c406fb5e498a5a0123f2d087a5b9d9c2

commit df9f7af7c406fb5e498a5a0123f2d087a5b9d9c2
Author: Xianzhu Wang <wangxianzhu@chromium.org>
Date: Thu Sep 27 21:23:22 2018

[PE] Fix crash when checking eligibility of effect node's output clip

Previously ContainingBlockFor(Fixed|Absolute)Position was used to get
the clip state of the container of fixed|absolute descendants. However,
if the container is not a LayoutBlock, the mentioned functions will
return the containing LayoutBlock which may not be a layer thus may not
have LocalBorderBoxProperties to get the clip state.

Now use ContainerFor(Fixed|Absolute)Position instead, and add test.

Bug:  889734 
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I6a1c95f81259a566791b40867b666b5c9852066a
Reviewed-on: https://chromium-review.googlesource.com/1249827
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594866}
[modify] https://crrev.com/df9f7af7c406fb5e498a5a0123f2d087a5b9d9c2/third_party/blink/renderer/core/layout/layout_object.h
[modify] https://crrev.com/df9f7af7c406fb5e498a5a0123f2d087a5b9d9c2/third_party/blink/renderer/core/paint/paint_property_tree_builder.cc
[modify] https://crrev.com/df9f7af7c406fb5e498a5a0123f2d087a5b9d9c2/third_party/blink/renderer/core/paint/paint_property_tree_builder_test.cc

ClusterFuzz has detected this issue as fixed in range 594865:594871.

Detailed report: https://clusterfuzz.com/testcase?key=5155425048330240

Fuzzer: marty_html_twiddler
Job Type: linux_ubsan_vptr_content_shell_drt
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000058
Crash State:
  blink::FragmentData::PostOverflowClip
  blink::PaintPropertyTreeBuilder::UpdateForSelf
  blink::PrePaintTreeWalk::WalkInternal
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_content_shell_drt&range=594510:594512
Fixed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_content_shell_drt&range=594865:594871

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5155425048330240

See https://github.com/google/clusterfuzz-tools for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 5155425048330240 is verified as fixed, so closing issue as verified.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.